大鼠延髓至下丘脑室旁核的儿茶酚胺能投射神经元在胃伤害性刺激后的FOS表达

用ＨＲＰ注入下丘脑室旁核逆行追踪与抗Ｆｏｓ和抗酪氨酸羟化酶（ＴＨ）双重免疫细胞化学相结合的三重标记方法，对大鼠孤束核和延髓腹外侧区至下丘脑室旁核的儿茶酚胺能投射神经元对胃伤害性刺激后的ｃ－ｆｏｓ表达进行了观察，发现孤束核和延髓腹外侧区有７种不同的标记细胞：ＨＲＰ、Ｆｏｓ、ＴＨ单标细胞，Ｆｏｓ／ＨＲＰ、Ｆｏｓ／ＴＨ、ＨＲＰ／ＴＨ双标细胞，Ｆｏｓ／ＨＲＰ／ＴＨ三标细胞。上述７种标记细胞主要分布在延髓中、尾段孤束核的内侧亚核、连合亚核和延髓腹外侧区以及两者之间的网状结构。ＨＲＰ标记细胞以注射侧为主，对侧有少量分布。本文结果证明，大鼠孤束核和延髓腹外侧区至下丘脑室旁核投射的部分儿茶酚胺能神经元可能参与胃伤害性刺激的传导和调控。

CATECHOLAMINERGIC NEURONS IN MEDULLARY PROJECTING TO THE PARAVENTRICULAR NUCLEUS OF THE HYPOTHALAMUS DISPLAY FOS EXPRESSION VISCERAL NOXIOUS STIMULATION OF STOMACH IN THE RAT

In the present study, a triple labeling method, in which horseradish peroxidase(HRP) retrograde tracing was combined with Fos and tyrosine hydroxylase(TH) immunohistochemical staining, was used.RP was stereotaxically injected into unilateral paraventricular nucleus of hypothalamus(PVN) in the rat,after survival for 48h.formalin was introduced into the stomach asvisceral noxious stimulus.Then the animals were allowed to survive for 2h and sacrificed. Under light microscope, seven kinds of labeled neurons were found in the sections of medulla: Fos-like immunoreactive (LI)neurons, TH-LI neurons,HRP retrogradely labeled neurons, Fos/HRP,Fos/TH ,HRP/TH double labeled neurons,and Fos/HRP/TH triple labeled neurons. These different labeled neurons were mainly observed within the medial subnucleus and commissural nucleus of the nucleus tractus solitarii(NTS), ventrolateral medulla(VLM ) and the reticular formation(RF)between NTS and VLM of middle and caudal segments of medulla. Within the medulla,HRP labeled neurons were mainly located on the ipsilateral side to the HRP injection site. These results indicated that some catecholaminergic neurons in the NTS,VLM and RF projected to the PVN and received the visceral noxious stimulation. This ascending pathway from the NTS,VLM and RF to the PVN might involve in the transmitting process of stress responses to the visceral noxious stimulation.